bug#29038: df hangs on fifos/named pipes

[Jim Meyering]

On Sun, Oct 29, 2017 at 3:34 PM, Pádraig Brady <address@hidden> wrote:
...
>> That was discovered by Martijn Dekker, CCed, when looking for a
>> portable way to identify the file system of an arbitrary file.
>
> Yes we shouldn't hang.
>
> RE side effects, open() is a fairly innocuous operation,
> and we expect stat() to have side effects to auto mount.
> (Note we avoid stat() with non specified arguments if possible due to this):
> https://git.sv.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=v8.27-92-ga19ff5d
>
> I suppose we could stat() and if that succeeds && !fifo, only then call 
> open() ?
> Patch to do that is attached.

Sounds good. Patch looks fine to me. Thanks!